The production of aldehydes from hydrocarbons is known in the art, but in general, such production requires an expensive starting material or the initial production of intermediates. Thus, for example, in producing acetaldehyde from a hydrocarbon, the starting material is generally ethylene, an expensive starting material. In the production, for example, of benzaldehyde, the starting material can be toluene, but the toluene generally then must be converted to a chlorosubstituted intermediate which is subsequently converted to benzaldehyde.
Three patents, all assigned to the Lummus Company, disclose processes for preparing aldehydes by reacting an alkane with an oxygen-containing gas in a molten mixture of the higher and lower valent forms of a multivalent metal chloride. U.S. Pat. No. 3,641,157 discloses such a reaction generally, whereas U.S. Pat. Nos. 3,869,518 and 3,939,209 focus more specifically on the production of acetaldehyde from ethane in such a molten metal chloride mixture. Unfortunately, the use of these molten metal chlorides is highly undesirable due to the corrosiveness of the materials. Moreover, the selectivity to aldehyde production of such a process is less than might be desired, as detailed in the comparative working examples given hereinbelow.
Accordingly, it would be highly desirable to provide a new process for producing aldehydes which is simple, direct and does not suffer from the abovementioned corrosiveness problem. In addition, it would be highly desirable to provide a process that offers excellent selectivity to the desired aldehyde.